Machine to machine (M2M) technology refers generally to the ability of machines, devices, and assets, particularly those that are distributed or remote, to exchange information with people and/or with a corporate management system. Although a precise definition of M2M is difficult to formulate, M2M generally encompasses the use of telemetry via networks including, but not limited to, public wireless networks.
Historically, telemetry systems were limited to applications for conglomerates and other well-financed organizations. Large oil and gas companies and electric utilities, through the use of extensive customer built dedicated data networks, were among the first private organizations to use telemetry widely. More recently, however, the cost of access to public wireless data networks has been dropping while the capabilities of these networks has been increasing thus making M2M concepts feasible for a much larger audience.
The M2M systems described herein generally include remotely located machines or devices referred to as field assets. Although field assets may encompass any variety of specific types of machines (oil rigs, cellular phone system base stations, ATM machines, and weather monitors), the specific embodiments described herein are in the field of vending machines. Vending machines are unmanned, electro-mechanical devices that dispense products including consumable products such as soft drinks and snack foods in exchange for cash or other form of payment. Vending machines are generally deployed as remotely located field assets by a company that manages a plurality of such devices.
In the field of vending machines, the traditional extent of automation consisted primarily of the ability retrieve “snapshots” of inventory data from a vending machine using a wired, handheld device and a specialized, industry standard, data exchange (DEX) protocol and interconnect. DEX is a communication protocol for the electronic retrieval of machine-level transactions via data polling. While DEX has served its purpose well for a considerable period of time, DEX is not capable of analyzing vending machine sales beyond the most superficial level. Nor is DEX capable of providing information that could be used to manage a vending machine from a maintenance perspective. Moreover, a DEX polling event effectively takes a vending machine off line, even if for only a short duration. This limitation prevents it from serving as a real time transaction monitoring protocol.
More recently, the Multi Drop Bus/Internal Communication Protocol (MDB/ICP or, more simply MDB) vending machine technology has evolved. MDB defines a bus interface and standard for electronically controlled vending machines. Unlike DEX, MDB provides a control mechanism and standard for the various peripheral devices typically encountered in a vending machine. Moreover, MDB supports a level of time stamping that enables insight into information that is potentially valuable to a vending machine company. Despite the opportunities for expanded functionality and data insight offered by MDB, conventional MDB compliant vending machines tend to utilize MDB merely as an interconnect between a VMC and one or more peripherals and, possibly, a source of DC power.
Nevertheless, some efforts have been devoted to adding functionality to conventional vending machines. For example, U.S. patent application Ser. No. 10/722,954, referred to above, describes a processor-based audit device having access to the MDB bus and to the VMC via a DEX port. Using this audit device, a vending machine can greatly improve the amount and quality of information concerning sales. If, for example, sales of a particular vending machine vary considerably from day to day and even within a day, conventional DEX polling, which might take place on a weekly basis, for example, will not be able to identify these variations and the inability to do so could result in lost sales opportunities. Using such an audit device, a vending machine can retrieve and store a plurality of DEX downloads together with information from which time stamps can be derived for each DEX download.
As another example, U.S. patent application Ser. No. 11/464,127, referred to above, describes systems and methods for using a MDB packet capture agent or snoop agent to extend the functionality of vending machines to encompass information that is outside the scope of DEX or to capture and enhance traditional DEX data without performing a DEX download. Capturing packets directly from the MDB serves a variety of purposes including, as examples, enabling feedback of field asset performance and customer behavior in real time, without requiring a DEX polling event, uncoupling field asset monitoring from the DEX standard, and facilitating the gathering of quantifiable, time-based consumer behavior data.
While the ability to snoop MDB data represents an advance a vending machine management, it would be still further desirable to use such captured MDB data to determine operational parameters associated with the vending machine. For example, it would be beneficial to monitor when a door to the vending machine is opened and closed. Monitoring when a door is opened and closed may allow a vending machine owner to have a detailed record of when a vending machine is accessed, for example, to permit a vending machine operator to determine if the vending machine has been accessed without authorization. Under traditional approaches, an electronic door switch is electronically coupled to a vending machine controller and communicates signals to the vending machine controller indicating when the door is opened and closed. However, in these traditional approaches, the signals from the door switch are not communicated over either of the DEX or MDB busses of a vending machine, and thus are difficult to log without adding additional hardware and design complexity. One traditional solution to this problem has been to equip the vending machine with a second electronic door switch that is coupled to either of the DEX or MDB busses of the vending machine. However, this solution requires additional design complexity and cost.